Carbureter



J. 0. CUNNINGHAM.

CARBURETER.

APPucATioN FILED MARA 23. 1920.

Patented June 21, 1921..

PATENT OFFICE.

JAMES 0. CUNNINGHAM, OF INDIANAPOLIS, INDIANA..

CARBURETER.

To all whom it may concern Be it known that I, JAMES O. CUNNING- HAM, citizen of the United States. residing at Indianapolis, in the county of Marion and State of Indiana, have invented certain new and useful Improvements in Carbureters, of which the following is a specification.

The present invention relates to a fuel feeding device for internal combustion engines, and has for its object to provide an invention of this character which enibodies novel features of construction wherebv the partial vacuum of the intake manifold mali1 be utilized to lift the liquid fuel from a tank located at a low levelto a carburetor located at a higher level, thereby avoiding the necessity of using some auxiliary apparatus such as a vacuum tank for this purpose.

Further objects of the inventionl are to provide a' fuel lifting device of this character which can be embodied in the construction of a `float feed carbureter without interfering with the proper functioning of the carbuieter, which .will operate electively at all engine speeds, and which will insure an adequate supply of gasolene or other liquidA fuel to meet the requirements of the engine under all working conditions.

`With these and other objects in view the invention consists in certain combinations, arrangements and associations of the parts, which will more fully appear as the del scription proceeds. the novel features thereof being pointed out in the appended claims.

For a full understanding of the invention reference is to be had to the following description, and accompanying drawings, in which:-

Figure 1 is `a Vertical sectional view through a carbureter constructed in accordance with the invention.

Fig. 2 is a horizontal sectional view through the same, taken on the line 2-2 of Fig. 1 and looking in. the direction of the arrows.

Fig. 3 is a similar view, taken on the line 3-3 of Fig. l and looking in the direction of the'arrows.

Figs. 4 and 5 are detail views of the mouth piece for the suction tube and the air detiectoi` ich is associated therewith.

Corr onding and like parts are referred `to in t' following description and indi Speccation of Letters Patent.

raieuted June 21, 1921.

Application 1ed March 23, 1920. Serial No. 368,080.

cated in all of the views ot' the diaivino bv like reference characters. D

(lne possible embodiment of the invention has been illustrated b v the drawing and will be described for thc purpose of explaining the general idea oi' the invention. although it will be understood that inanv modifications and changes can be made without departing from the `spirit and scope of the iuveiitioii. The carburetor shown is of the compound nozzle tlvpe. and the construction und operation ot the carburcter will inciclv be explained briell'v. since carburcters ot' this type are well known in the art and no claim to novelty is based thereon. The iioat chamber l is loscrl at itstop by a cover plattl 2. and coninnuiicatcs at its base with a passage 3 which leads to the base ot a main jet 4. A cap jet 5 surrounds the main jet and communicates at its lower end with a passage 6 leading latta-alli' from a well T which is shown as formed in the body ot the carbureter intermediate of the tioat` chamber l and mixing chamber 8.

The lower end of the well T communirates through a restricted port 9 in a conipeiisator plug lll with the passage 3. so that. under normal conditions the liquid fuel will rise in the well until it reaches the level ot the fuel in the float chamber. Removable plugs ll at the bottoni of the carbureter enable access to be had to thc compensator plug 1l) and main jet l when such is neces- Sarv. A choke or "venturi` is fitted in thc mixing chamber 5 and operates in the well known manner to produce a rotative or spiral motion of the air which is drawn into the mixing chamber through the air intake l2. The usual throttle valve 13 is arranged in `the upper end ot' the mixture passage and operates in the usual manner to govern the speed of the engine bv controlling the suppljvv of explosive mixture thereto.

The level of the liquid fuel within .the float chamber 1 is automatically control d by the action of a float 14` said float havin a` guide stein 15 at the lower end thereo and being provided at its upper end with a needle valve 1G which controls the entrance of liquid fuel into the fioat chamber through a fuel inlet 17 at the top thereof. The upper end of the well 7 communicates through a` primin optning 18 with the mixture rpassage o the mixing chamber at a point adchamber lill jaeent the throttle valve 13, and the effective Size ot' this primingfiipening is controlled by a needle valve t9.. When starting the engine, the throttle lvalve is only partially opened, and fuel will be drawn through the priming openlng n18 to provide a rich starting mixture.

Vhen the engine is in operation the quantity of fuel that can be drawn through the cap jet 5 is'limyited by the flow of fuel `through the restricted port after the initial supply ol-` fuel in the well 7 has been exhausted. The result is that at low engine peeds the spray from the cap jet 5 is Stronger than that from the main jet 4, although as the engine gains speed and the suction beeomes greater, the main jet 4 gains in strength while the cap iet 5 becomes weaker. Both jets are in action at all speeds, and the defect ot one jet, starting poor and growing rieher until it is about right at high speed, is compensated by the defect of the other jet which starts too poor and keeps growing poorer. One supplements the other so that at every motor speed there is asuhutantially constant ratio of air and gasolene to Supply elticient combustion.

A suction pipe E20 leads from an opening 21 in the top of the float chamber to a port 22 arranged at one side of the mixture passage of the mixing chamber 8 at a point below the throttle valve 13. A. plate E23 which, as indicated hy Fig. 5. may he suhetantially V lhaped in formation, is arranged in the mixture passage so as to provide an upwardly openingr flared or t'an shaped mouth for the suction pipe 2l). rllhe upper' end of the mouth terminates at a point adjacent the upwardly Swinging edge ofthe throttle valve when the latter is at ila4 closed position` and the mouth is curved to conform to the curvature ot the walk ol the mixing chamber. Associated with this mouth plate Ql is an inclined air delleetor plate or tin 24. rlhc inclination ol' thi air dellector plate 24 will cause a high velocity jet olA air or l'nel mixture to paas the upper edge ol the mouth plate, 22S when the engine ia in operation. and this will operate in the well known manner to produce a partial vacuum in the Huetion pipe 20. Thia partial vacuum will lie transmitted to the float l where it will operato to lift the. liquid fuel from a tank located at a loiv level and automatically draw the fuel into lla float chamber ae perinittcd hy the float valve to maintain the fuel within a float, chamber ai a constant level.

'|`l|e top ol' the lloat chamber is provided with :in air inlet E25 which is controlled by :t cheek valul 2li. This check valve iS normally held in a rlo-ed poxilion liv a `\pring 2T, and the tension ol' thi `epring can lle governed by arri-wing the cap piece 2H ol' the check valve flown or up on the nipple nl' llie .wir inlet opening. 'tliie cheek valie control llaA ilegree of vacuum that can be produced within the float chamber, since as soon as a predetermined degree of vacuum has been produced within the float chamber the check valve will automatii'fally open and permit atmospheric air to enter the float chamber until the vacuum drops to the proper point. This prevents the vacuum in the float chamber troni, becoming as perfect or strong as the vacuna in the mixing chamber 8. In other words, there will always be a stronger vacuum in the mixing chamber than in the float chamber, so that there will be no possibility of the partial vacuume` in the two chambers eounterbalancing each other and preventing the feeding of fuel from the llo-at chamber to the or nozzles. At the same time a vacuum of suflicient intensity to lift the liquid fuel from a tank at a lower lever and draw it into the float chamber, as is necessary to meet the requirements of the engine, is maintained in the float chamber. This vacuum is even produced at low s eeds, since the air deflector plate or fin 24 o the mouth plate 225 will produce Suction through the pipe 2l) when the throttle valve 13 is practically clos-ed for the idling speed of the engine. The gasolene or liquid fuel is thus lifted from a tank at a lower level and automatically fed to the float chamber of the carbureter as is necessary` without the necessity of using any auxiliary appa ratua .auch as the conventional vacuum tank tor lifting the fuel.

Having thus described my invention, what l claim as new is1- l- The combination with a earhurcter formed with a mixture passage., a suction pipe communicating with the mixture paseage. fuel lifting moana associated with the suction pipe, and air defleeting means arranged within the mixture passageof the carhureter for directing a high velocity jet of air across the mouth of the suction pipe.

2. Il`he cinnbination with a carburetor Vformed with a mixture passage, of a `auction pipe communicating with the mixture passage, fuel lifting means associateel with the suction pipe, a mouth picco for the suction pipe. and an inclined air dcflcetor arranged within the. mixture passage of the carhureter and positioned lo direct a jet of air across the orifice ol the mouth piece.

il. The combination with a. earhureter formed wil h a mixture passage, of a. throttle valve, a auction pipe leading from the mixture passage, fuel lifting means associated with the suction pipe, a mouth piece for the ymii-tion pipe, said mouth piece having au oriliee which ia positioned adjacent the throttle valve. and an inclined air delleelor arranged within *he mixture paseage and associated with the mouth piece to direct a ict of ail' :Ii'ro` e the orifice thereof.

l. 'l`lie combination with a. carburetor loo im; a Iloal valve chamher and a mixture lli) lli il? passage, of a suction pipe leaning from the mixture passage to the Host valve chamber, a mouth piece for the suction pipe at the end thereof which communicates with the mix- 5 ture passa e, an inclined air deleotor arranged wit in the mixture passage and associated with the mouth piece to deflect an 

